Cobra 26 presser/walking foot marking up leather

[AtomicLeathers]

Hello sewing machine guru’s!

   I am having trouble with my brand new Cobra class 26 machine. When I sew with the machine, the pressure foot/walking foot press the leather hard and it makes a trail on the leather. It makes a beautiful stitch but right next to it, there is a presser foot/walking foot impression. 

    I have adjusted the “banana slide” on the back,  checked both my feet for any adjustment and there is none.

     Right now im sewing 2 , 8-9oz pieces of  Wickett and craig traditional harness in med brown and it marks it pretty darn good.

     I called the leather machine company and a guy told me to cut off the spring 5mm.  Just doesn't sound right that I need to cut anything, especially  since its brand new?

    Please help if anyone can with any ideas or input.  Thank you!!

[Tequila]

Watching

[Constabulary]

have you tried to reduced the foot pressure?

[AtomicLeathers]

4 minutes ago, Constabulary said:

have you tried to reduced the foot pressure?

How do I reduce the pressure of the foot?  There is the threaded rod and jam nut on top, I backed that all the way off, and under that is the spring they told me to cut off 5mm off

[Constabulary]

should be mentioned in the manual how to reduce foot pressure. That's a quite basic thing every sewing machine operator should know.

You need just enough foot pressure that the rising needle is not lifting up the material you want to sew. Thicker / more dense material with thicker needle and thicker thread require more foot pressure because of more friction between needle and material. But the thinner the material and the thinner the needle the less foot pressure you need.

EDIT:

Edited April 15, 2022 by Constabulary

[AtomicLeathers]

26 minutes ago, Constabulary said:

should be mentioned in the manual how to reduce foot pressure. That's a quite basic thing every sewing machine operator should know.

You need just enough foot pressure that the rising needle is not lifting up the material you want to sew. Thicker / more dense material with thicker needle and thicker thread require more foot pressure because of more friction between needle and material. But the thinner the material and the thinner the needle the less foot pressure you need.

EDIT:

Yeeeeeeep That is the adjuster I tried moving. It is backed off all the way

[Constabulary]

then you either try to find a lighter spring or cut down the existing spring

[AtomicLeathers]

6 minutes ago, Constabulary said:

then you either try to find a lighter spring or cut down the existing spring

Seems weird that I have to cut the spring already on a brand new machine? Shouldn’t there be enough adjustment on it straight from the factory. thats why im checking to see if im missing some other adjustment rather then cutting the brand new machine

[Wizcrafts]

Ask Cobra if they can mail out a softer spring, or one that is already cut down and polished on the ends. There are soft and hard pressure springs for many types of machines. Some may be meant for a different brand but may fit in yours.

[suzelle]

Good luck Atomic. Looks like you have gotten some great advice here. I don't have a machine like yours, but would like to have something like it someday.

I wanted to say what Wiz said, why not just ask for another spring. I realize sometimes have to break things in and all that, but this spring thing is pretty fundamental. I have taken flattened springs out of old machines and stretched them out so they work again, and even trimmed one up before. But those were old machines. I did a little search and found a youtube video that went over the Foot Tension on the Cowboy  CB4500 machine and different things you could try. Good luck to you! Please let us know how you do!

 

 

[AtomicLeathers]

On 4/15/2022 at 6:33 AM, AtomicLeathers said:

Yeeeeeeep That is the adjuster I tried moving. It is backed off all the way

Hey where did you get that photo? In my manual, it looks like it is from 1990 haaa There is a section for the foot adjustment but it dosent have anything about 25mm height in it.  I cut 5mm off and it still is marking the leather up. Its at 25mm from the top of the nut to the bottem and the bottom of the top nut. If I release it anymore it comes out. and right now its pressing the leather to much. Do you think the leather is too soft? or maybe the spring is just new stiff and needs to work in?

Edited April 17, 2022 by AtomicLeathers

[AtomicLeathers]

22 minutes ago, AtomicLeathers said:

Hey where did you get that photo? In my manual, it looks like it is from 1990 haaa There is a section for the foot adjustment but it dosent have anything about 25mm height in it.  I cut 5mm off and it still is marking the leather up. Its at 25mm from the top of the nut to the bottem and the bottom of the top nut. If I release it anymore it comes out. and right now its pressing the leather to much. Do you think the leather is too soft? or maybe the spring is just new stiff and needs to work in?

this is from my manual. nothing about 25mm

[TomE]

Do you tap the stitches down after sewing?  I use a small hammer with a polished face and place the leather on a granite slab.  I am sewing bridle leather, not harness leather, with a Class 4.  The presser foot marks the leather when the thickness is > 20 oz.  even with the tension setting at a minimum. Tapping the stitches helps, and the marks fade somewhat with time.

[AtomicLeathers]

2 hours ago, TomE said:

Do you tap the stitches down after sewing?  I use a small hammer with a polished face and place the leather on a granite slab.  I am sewing bridle leather, not harness leather, with a Class 4.  The presser foot marks the leather when the thickness is > 20 oz.  even with the tension setting at a minimum. Tapping the stitches helps, and the marks fade somewhat with time.

ill try that. but gosh its crazy that it marks it up that bad. I seen others that just stitch and do a real good job the first time.  crazy.  ok ill see if I can hammer them down

[jrdunn]

I have a CB4500.  I have the presser foot tension fairly low.  It is not marking the leather, the needle foot is.  I haven't found how to reduce the tension on the needle foot.  @AtomicLeathers, It looks like at least some of your marks are made by the needle foot too.  I'd be very interested  to find out how to adjust it.  I haven't had my Cowboy long either.  Watching.

Jim

[Silverd]

Certainly the Presser foot marks can be eliminated by placing a strip of leather under it during the sewing process.  It's kinda a challenge to do this while still keeping an eye on things but after a while it becomes 2nd nature.  Of course. Reduce the spring pressure as much as you can, but this technique completely eliminates Presser foot marks in experience.  The needle foot marks are more difficult.  Short of an adjustment to reduce its down force what I have found is a few funny techniques that seem to work mostly pretty well but not 100% all of the time in all situations.

I sometimes case (wet) the top side leather pretty well then allow it to completely dry before sewing.  When dry, the previously cased leather is usually quite hard and better resists impression marking. Try it.  At least the Presser foot may not require a protective strip under it using this technique.  

After sewing, if needle foot marks are still prevalent i will lightly case top side only and use a hammer to gently pound the stitches, i then flex and bend and kneed with my fingers and stretch the stitch zone in an attempt to decompress the impression marks.  This method works pretty well but again is not 100% effective.  It usually improves things though.  Some machine tracks we have to accept or resort to hand stitching in areas where no marking is acceptable.  Thsts the difference between the work we do with a machine and fine leather working techniques that are used on very high quality pieces.   Finally, as the finished product ages, further reduction of Presser foot witness marks often diminish naturally with time and use.  

 

Silverd

 

[Wizcrafts]

Some compound feed walking foot machines have a second spring (and an adjuster) over the inside foot. If your Class 26 has that adjuster, back it off as far as it will go. You can even eliminate the spring on that foot if the adjuster doesn't clear them. Otherwise, try to find a softer presser foot spring.

The only machines I have owned or sewn on that don't leave marks around the needle are needle and awl machines, like the Union Lockstitch and Randall Lockstitch, and shoe patchers. These are jump foot machines with one presser foot that has legs outside the needle position. Unfortunately, patchers leave tooth marks from the foot, unless you cover them with heat shrink tubing (reducing the feedability).

[chrisash]

Is it me, but it looks like the stich length is varying along the sample shown, Maybe just the angle the photo was taken at

[TomE]

11 hours ago, AtomicLeathers said:

ill try that. but gosh its crazy that it marks it up that bad. I seen others that just stitch and do a real good job the first time.  crazy.  ok ill see if I can hammer them down

Just firm tapping.  I usually just tap on the backside with the front facing the granite slab.  It helps to smooth the stitch line and even out thread tension.  The marks probably won't be removed completely, but it should help.  A shorter/weaker spring is likely to be the best solution.